Lu Chih-Cheng, Huang Jeff
Institute of Mechatronic Engineering, National Taipei University of Technology, Taipei 106, Taiwan.
Department of Mechanical Engineering, National Taipei University of Technology, Taipei 106, Taiwan.
Sensors (Basel). 2015 Jun 19;15(6):14727-44. doi: 10.3390/s150614727.
A new class of tri-axial miniature magnetometer consisting of a planar fluxgate structure with an orthogonal ferromagnetic fluxguide centrally situated over the magnetic cores is presented. The magnetic sensor possesses a cruciform ferromagnetic core placed diagonally upon the square excitation coil under which two pairs of pick-up coils for in-plane field detection are allocated. Effective principles and analysis of the magnetometer for 3-D field vectors are described and verified by numerically electromagnetic simulation for the excitation and magnetization of the ferromagnetic cores. The sensor is operated by applying the second-harmonic detection technique that can verify V-B relationship and device responsivity. Experimental characterization of the miniature fluxgate device demonstrates satisfactory spatial magnetic field detection results in terms of responsivity and noise spectrum. As a result, at an excitation frequency of 50 kHz, a maximum in-plane responsivity of 122.4 V/T appears and a maximum out-of-plane responsivity of 11.6 V/T is obtained as well. The minimum field noise spectra are found to be 0.11 nT/√Hz and 6.29 nT/√Hz, respectively, in X- and Z-axis at 1 Hz under the same excitation frequency. Compared with the previous tri-axis fluxgate devices, this planar magnetic sensor with an orthogonal fluxguide provides beneficial enhancement in both sensory functionality and manufacturing simplicity. More importantly, this novel device concept is considered highly suitable for the extension to a silicon sensor made by the current CMOS-MEMS technologies, thus emphasizing its emerging applications of field detection in portable industrial electronics.
本文介绍了一种新型的三轴微型磁力计，它由一个平面磁通门结构组成，在磁芯上方中心位置正交放置一个铁磁磁通导向器。该磁传感器具有一个十字形铁磁芯，对角放置在方形励磁线圈上，在其下方分配有两对用于平面内磁场检测的拾波线圈。描述了该磁力计对三维场矢量的有效原理和分析，并通过对铁磁芯的励磁和磁化进行数值电磁模拟进行了验证。该传感器采用二次谐波检测技术进行操作，该技术可以验证V-B关系和器件响应度。微型磁通门器件的实验特性表明，在响应度和噪声谱方面，其空间磁场检测结果令人满意。结果，在50 kHz的激励频率下，平面内最大响应度为122.4 V/T，平面外最大响应度也为11.6 V/T。在相同激励频率下，在1 Hz时，X轴和Z轴的最小场噪声谱分别为0.11 nT/√Hz和6.29 nT/√Hz。与以前的三轴磁通门器件相比，这种带有正交磁通导向器的平面磁传感器在传感功能和制造简易性方面都有有益的增强。更重要的是，这种新颖的器件概念被认为非常适合扩展到采用当前CMOS-MEMS技术制造的硅传感器，从而突出了其在便携式工业电子设备中场检测的新兴应用。
